Demographic consequences of incest tabus: a microsimulation analysis

Theories of incest tabus usually stress the psychosocial advantages of marriage regulation. But marriage regulation may produce delays in mating and thus loss of fertility to a population. Computer microsimulation experiments measure the amount of fertility that must be achieved outside a normatively specified marriage system in order to keep population constant. This amount varies directly with scope of tabu and inversely with population size. For populations of hundreds it is negligible, but for populations of dozens it can be very great. In the latter, flexibility of marital arrangements may permit maintenance of fertility without repeated revision of rules of marriage.     

Tiliqua scincoides: temperature-sensitive units in lizard brain

Extracellular action potentials were recorded from units in the preoptic area of the brain of the Australian blue-tongued skink (Tiliqua scincoides) during periods of local heating and cooling of the brain (20 degrees to 36 degrees C) with water-perfused thermodes. In this temperature range most spontaneously firing neurons were temperature-insensitive, but eight showed sensitivity to the thermal stimulus. Five warm neurons increased their activity when the brain temperature was raised, and three cold neurons showed increased activity with fall in temperature.     

Recurrence of gastric dilatation-volvulus after incisional gastropexy in a rottweiler

An adult, castrated male rottweiler with a history of gastric dilatation-volvulus (GDV), which was treated 4 months previously by surgical gastric resection and incisional gastropexy, had a recurrence of clinical signs. Abdominal exploratory surgery revealed a 180 degrees -clockwise GDV, with a stretched adhesion at the original gastropexy site. The stomach was repositioned, and additional gastropexies were performed adjacent to the original gastropexy site and at the gastric fundus. The recurrence of GDV in this dog with an intact gastropexy suggested that a risk for volvulus remains after therapeutic incisional gastropexy.     

Postoperative results of unilateral arytenoid lateralization for treatment of idiopathic laryngeal paralysis in dogs: 39 cases (1996-2002)

OBJECTIVE: To evaluate postoperative results for dogs with idiopathic laryngeal paralysis that underwent unilateral arytenoid lateralization (UAL). DESIGN: Retrospective case series. ANIMALS: 39 dogs with idiopathic laryngeal paralysis. PROCEDURE: Medical records were reviewed, and information on surgical technique, hospitalization time, postoperative treatment, and complications was obtained. Owners were contacted by telephone for additional information if necessary. RESULTS: In all dogs, UAL had been performed by a single surgeon who used a standard surgical technique. Long-term follow-up information was available for all 39 dogs; mean follow-up time was 29.6 months (range, 3 to 61 months). Seven (18%) dogs developed postoperative pneumonia, and 6 of the 7 recovered with treatment. Twenty-two of the 39 (56%) dogs had minor complications, including unresolved coughing or gagging, continued exercise intolerance, vomiting, and seroma formation. Owners of 35 of the 39 (90%) dogs reported an improvement in postoperative quality-of-life score. Median survival time was 12 months; only 1 dog was euthanized because of respiratory tract disease following surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that UAL will improve quality of life in most dogs with idiopathic laryngeal paralysis. However, the complication rate is high, with postoperative pneumonia being the most important major complication. Minor complications were common but did not adversely affect owner-assigned quality-of-life scores in most dogs.     

The continuing u.s. Helium saga

Helium, resident in relatively high concentrations in certain natural gas fields in the United States, can be lost to the atmosphere when the natural gas is burned as fuel. In 1960, Congress amended the Helium Act of 1925 to provide for stripping natural gas of its helium, for purchase of the separated helium by the government, and for its long-term storage. In 1971, after about 28 billion cubic feet had been stored, the purchase program was terminated by the government, an action that unleashed several lawsuits and not a little acrimony. After more than a decade of controversy, much of the litigation has been concluded, much of the helium that could have been saved has been wasted to the atmosphere, and the gas fields supplying the helium are almost depleted. A new rich source of helium has been discovered in southwestern Wyoming that could ensure adequate supplies for many decades if an appropriate new federal policy on helium is developed and implemented.     

Effects of Glucose Concentration on in vitro Fertilization in BALB/c Mice

BALB/c mice are widely used in genetic, tumour and immunological studies. However, the mice demonstrate a lower reproduction rate, low fertility and small litters, because of their highly genetic homozygoisty. Based on in vitro fertilization (IVF), a routine technique for biomedical studies, it is worth to evaluate the effects to BALB/c mice on IVF efficiency. In order to test the genetic factor affecting the IVF efficiency of BALB/c, four reciprocal IVF tests of BALB/cByJ and FVB/NCrl mice were performed. The results showed that the average fertility of IVF sponsored by FVB/NCrl spermatozoa was 69.6%, but only 12.1% was obtained from BALB/cByJ strain. Effect of glucose contained in the culture medium to the IVF efficiency of BALB/cByJ was also evaluated. The results showed that the fertility of BALB/cByJ spermatozoa incubated with 0, 2.7, 5.5, 11.1 and 22.2 mm of glucose in the TYH medium were 6.8, 9.9, 13.9, 32.7 and 22.2%, respectively. It is showed that IVF efficiency of BALB/cByJ spermatozoa could be improved depending on the concentration of glucose in the IVF medium. According to the results, it is beleived that lower IVF of BALB/cByJ mice might be due to the genetic defect in spermatozoa and increasing glucose in the IVF medium which significantly affect the IVF efficiency of BALB/cByl via activating the spermatozoa.     

Water and bromide transport in a heterogeneous glacial sand

We investigated water flow and bromide transport under agricultural field conditions, using TDR and tensiometer measurements as well as a bromide tracer experiment. The soil, an Albic Luvisol consisting of sand covering glacial loam, is highly heterogeneous with polygon nets formed by sand‐filled frost wedges. Water flow and bromide transport are influenced by the thickness of the glacial sand horizon and the soil structure. Both cause a variation of the actual evapotranspiration up to ± 25 mm/yr. Water and bromide are preferentially transported on the inclined soil layer boundaries into the sand wedges. From there infiltrating water may be redistributed into the surrounding glacial till. Approximately, the depths of the bromide centers of mass can be deduced using the piston flow concept. Small‐scale mass balances of the tracer show that vertical sections with bromide deficits and bromide surpluses are well balanced within a horizontal range of 1.8 m to 2.8 m. This distance is interpreted as the lateral influence of the sand wedges.     

Quantitative high-throughput analysis of 16 (fluoro)quinolones in honey using automated extraction by turbulent flow chromatography coupled to liquid chromatography-tandem mass spectrometry

A method making use of turbulent flow chromatography automated online extraction with tandem mass spectrometry (MS/MS) was developed for the analysis of 4 quinolones and 12 fluoroquinolones in honey. The manual sample preparation was limited to a simple dilution of the honey test portion in water followed by a filtration. The extract was online purified on a large particle size extraction column where the sample matrix was washed away while the analytes were retained. Subsequently, the analytes were eluted from the extraction column onto an analytical column by means of an organic solvent prior to chromatographic separation and MS detection. Validation was performed at three fortification levels (i.e., 5, 20, and 50 microg/kg) in three different honeys (acacia, multiflower, and forest) using the single-point calibration procedure by means of either a 10 or 25 microg/kg calibrant. Good recovery (85-127%, median 101%) as well as within-day (2-18%, median 6%) and between-day (2-42%, median 9%) precision values was obtained whatever the level of fortification and the analyte surveyed. Due to the complexity of the honey matrix and the large variation of the MS/MS transition reaction signals, which were honey-dependent, the limit of quantification for all compounds was arbitrarily set at the lowest fortification level considered during the validation, e.g., 5 microg/kg. This method has been successfully applied in a minisurvey of 34 honeys, showing ciprofloxacin and norfloxacin as the main (fluoro)quinolone antibiotics administered to treat bacterial diseases of bees. Turbulent flow chromatography coupled to LC-MS/MS showed a strong potential as an alternative method compared to those making use of offline sample preparation, in terms of both increasing the analysis throughput and obtaining higher reproducibility linked to automation to ensure the absence of contaminants in honey samples.